Even with Jason Vargas on the mound, when small bunches usually suffice.

Whit Merrifield hit a bases-loaded triple in a six-run sixth inning and Vargas became the American League's second nine-game winner, leading the Royals to an 8-1 victory over the San Francisco Giants on Tuesday in the opener of a two-game interleague series.

"We've been doing some nice things offensively lately," noted Vargas (9-3), who moved into a tie with Houston's Dallas Keuchel for the AL lead in wins. "We'll try to keep it going as long as possible."

Merrifield and Jorge Bonifacio drove in three runs apiece in a 15-hit attack for the Royals in a matchup of teams that went head-to-head in the 2014 World Series.

San Francisco won the 2014 championship, but Tuesday's win improved the Royals' regular-season record against the Giants to 11-4.

"Tons of memories," Vargas said of the Giants' seven-game triumph in 2014. "We came up short. That's the way it goes sometimes. But there's the bonds that you build."

The Royals scored seven of their eight runs off Giants starter Ty Blach (4-4), who had allowed a total of just seven runs in his previous five home starts this season.

"It's a game of inches," said Giants manager Bruce Bochy, suggesting the game was closer than the final score would indicate. "We're just not quite getting to some of these balls (in the field). I think you've got to attribute bad luck to it for the most part."

In winning for the sixth time in its last nine road games, Kansas City led just 2-1 before busting the contest open with the six-run sixth.

Merrifield's three-run triple came after Alcides Escobar's two-run double had increased the Royals' advantage to 4-1.

"It was one of those you don't hit very well, but you see it going in a good spot," Merrifield said of his sliced flyball down the right field line that barely eluded a diving Hunter Pence. "I saw it dying ... That was beautiful."

Bonifacio completed the uprising with an RBI single that scored Merrifield to make it 8-1.

The Royals have scored a total of 31 runs on a four-game trip that opened with three games in San Diego. Nineteen of those runs have been the product of four-, six- and nine-run innings.

The six-runner Tuesday allowed Vargas to coast. He called it a night after completing seven innings during which he allowed five hits and one run. He walked one and struck out six in his 102-pitch effort.

He won his fourth straight decision, having allowed a total of five runs over that stretch.

"To have that kind of success and to sustain it this far into the season, is fantastic," Vargas gushed.

Merrifield, Bonifacio, Escobar, Salvador Perez, Mike Moustakas and Alex Gordon had two hits apiece for the Royals, who were visiting San Francisco for the first time since the 2014 World Series.

Escobar and Gordon each scored two runs.

Along with the seven runs, Blach gave up 10 hits in his 5 2/3 innings. He walked one and struck out four.

Buster Posey and Austin Slater had two hits apiece for the Giants, who split a pair with the Royals in Kansas City earlier this season.

The Giants have been held to no more than one run on 17 occasions this season.

Blach easily could have had a 1-2-3 third inning instead of the two runs allowed on four hits.

The Royals loaded the bases on a ground ball by Escobar that barely eluded Giants first baseman Brandon Belt, a blooper by Gordon to short right field that tipped off the glove of second baseman Aaron Hill, and a bunt by Vargas that was placed perfectly between Blach and third baseman Eduardo Nunez.

Even Bonifacio's hard-hit, two-run single could have been caught, but Blach's stab at the liner came up empty and the ball rolled into center field, scoring Escobar and Gordon, giving Kansas City a 2-1 lead.

"That's just baseball," Blach lamented. "A couple of bad bounces and then you don't make pitches when you have to ... It's going to humble you in a hurry."

The Giants had opened the scoring an inning earlier on the first of Posey's hits, a leadoff double, followed by Pence's infield out and Brandon Crawford's sacrifice fly.

NOTES: Royals 2B Whit Merrifield's triple was the sixth of his two-year career, his first with more than one runner on base. ... Royals LF Alex Gordon's two hits increased his career total to 1,274, allowing him to pass DH Billy Butler for seventh place on the franchise's all-time list. ... Royals manager Ned Yost announced before the game that LHP Matt Strahm will replace LHP Eric Skoglund in the starting rotation, beginning Thursday against the Los Angeles Angels. ... The Golden State Warriors' championship clinched Monday night was their third since moving west, tying the Giants for third place among San Francisco Bay Area professional teams behind the San Francisco 49ers (five) and Oakland Athletics (four). The Giants' three World Series titles in 2010, 2012 and 2014 were all won on the road. ... The Giants have not won an interleague series at home since July of 2015.